But is the threat of high temperatures that come in below zero and wind chills as low as -26 degrees enough for local schools to call off classes?

Indianapolis Public Schools spokeswoman Carrie Cline Black Local said the decision isn't as simple as just looking at the forecast and saying yea or nay.

"On a specific morning or in a window of time that we're looking at, conditions could be different in multiple parts of our district," Black said. "So it is not an exact science, but we do take it very seriously and we do make the decision that's in the best interest of the majority of our students and our families."

IPS has a general guideline that school will be delayed or canceled if conditions could lead to frostbite in 10 minutes or less. But classes can be canceled in less extreme conditions. According to the NOAA chart, wind speed would need to reach 55 mph for frostbite to strike in 10 minutes if the air temperature is 0 degrees.

At -5 the wind would need to hit 35 mph, and at -10 wind speeds would need to measure at least 25 mph.

"We try not to put specific numbers on it because there are so many variables," Black said. "We've been monitoring the forecast since last week. If we can make the call the night before, we certainly will. We want to give parents as much of a heads up and an opportunity to plan ahead as possible, and sometimes in cases like this we can make the call the night before."

The M.S.D. of Wayne Township takes a similar approach and monitors the hourly NOAA temperature predictions.

If the air temperature is predicted to be 10 below zero or colder at 7 a.m., the school will consider a two-hour delay. If the air temperature is predicted to stay at 10 below zero or colder by 9 a.m., the school will consider closing.

"Such a determination will be made as early as possible, perhaps the evening before, but certainly by 6 a.m.," said a statement from M.S.D. of Wayne Township.

District officials explain that wind chill prediction isn't as accurate as temperature prediction because of the variability wind speed based on time and location.

"While NOAA observations and predictions are based upon the open conditions of the Indianapolis Airport, these conditions are often different throughout Marion County," according to a statement from school officials. "Local observations of wind speed will affect the decision regarding delaying or closing school."

The district says wind chill concerns emerge at a predicted wind chill temperature of -19 degrees.

Officials at Noblesville Schools say they use a comprehensive plan whenever a school delay or eLearning day caused by weather is a possibility. This includes a team that monitors weather and roads, and Superintendent Beth Niedermeyer will often personally drive the roads as part of the assessment team.

The decision to delay school at Noblesville is based on factors such as time needed for roads to be cleared, giving buses the time to warm up and checking to see if harsh conditions at the start of the day persist.

An eLearning day will be used if roads are deemed impassable, buses are unable to run or state/county weather emergencies call for widespread facility closures.

Officials added that because of the eLearning option, school closures due to inclement weather are no longer the norm. But closures may still occur in the event of an unexpected weather event that doesn't give teachers enough time to prepare eLearning materials.

"Parents often ask why delays and eLearning announcements are typically called in the morning (and sometimes at the last minute) instead of the night before," said a statement from Noblesville Schools. "While we realize this timing can be more challenging for some parents, our top priority is for school to be in session as long as it's safe to do so. Most often there is a need to study forecasts, drive roads and assess conditions in the early morning as weather and road conditions change frequently."

When it comes to road conditions, IPS works with Durham School Services, the district’s transportation contractor, to make sure that getting to and from school safely as possible. Five drivers, three from IPS and two from Durham School Services, hit the streets early and drive in different areas of the district.

They drive both main streets and side roads to get as complete a picture of conditions as possible. They also consider amount and type of precipitation, temperature/wind chill, visibility, status of clearing roads, status of clearing sidewalks, refreeze of melted snow/ice from previous day, blowing snow and continued snow in the forecast.

By 4:45 a.m., drivers compare conditions across the city to agree on a recommendation to share with the superintendent. By 5 a.m., the Deputy Superintendent for Operations calls the superintendent to share the recommendation of the team and discuss options for the day.